Mobile data demand is being met through a multitude of technologies: wireless wide area networks such as WCDMA and LTE, wireless local area networks such as IEEE 802.11, and wireless personal area networks such as Bluetooth.
Wireless wide area wireless networks are typically accessible to a mobile device if and only if the mobile device has data transfer capacity in the wireless wide area network, given by a “data plan” contract between the user of the mobile device and a network operator. Such a data plan contract may include an unlimited amount of mobile data, but is very often capped to a maximum monthly consumption, measured in megabytes. When the allotted amount of data has been consumed, the user may be offered to purchase additional mobile data from the network operator, causing an undesirable additional higher cost. On the other hand, if a portion of the allotted amount of data has not been consumed within a certain period, usually a month, that portion is forfeited by the user without any compensation by the network operator. Optionally, the network operator might offer the user the possibility to save unused data portions up to a certain limit and for a limited amount of time.
A user may lack a satisfactory Internet connection for several reasons: (i) the user may not have a data plan; (ii) the user may have already consumed his allotted monthly mobile data and is unable or unwilling to purchase additional mobile data from the network operator; (iii) the user may be travelling, having no access to present wide area networks except through roaming, which may be prohibitively expensive; (iv) the user may be connected to a congested wireless local area network.